Tabletop Conquest is a solo dice wargame, perfect for sharpening the mind in odd hours.
You play the commander of a medieval army, attempting to conquer a randomly-generated foreign land. You must use the land's resources to build your troops as you fight towards the enemy capital and defeat its massive army.
The game is played with a single six-sided die and some paper. And it's free.
Download version 2012-08-22